Is cancer treatment safe during pregnancy?

A healthy living blog from Marshfield Clinic Health System

Nov 7, 2017

Pregnant woman sitting crossed legged writing in a notebook - Cancer treatment and pregnancy — Being diagnosed with cancer during pregnancy is rare. If it happens, a team of specialists work to keep the mother and baby safe.

Cancer diagnosis during pregnancy is rare. However, breast cancer, cervical cancer and melanoma are the most common cancers found in pregnant women.

Though it sounds scary, cancer diagnosed during pregnancy often is successfully treated without harming the woman or the baby.

“Pregnancy doesn’t necessarily cause worse cancer outcomes, but the type and timing of treatment need to be planned carefully,” said Dr. Arlene Gayle, a Marshfield Clinic oncologist/hematologist.

Don’t delay testing if you’re pregnant

Routine tests like Pap smears during pregnancy sometimes detect cervical cancer. However, mammography isn’t routinely done during pregnancy, and breast cancer diagnosis might be delayed unless the woman sees her doctor about symptoms.

See your doctor immediately if you have symptoms that could be cancer, like a lump in your breast or a suspicious mole. Early detection is important during pregnancy. Your doctor will need to know how much the cancer has progressed and how quickly it is spreading in order to recommend a treatment plan.

You may be concerned about getting certain diagnostic tests while pregnant. Mammograms can be performed safely if the mother’s abdomen is shielded. MRI without contrast may be used to plan treatment. Ultrasounds, Pap smears and biopsies don’t harm the baby.

Some cancer treatments are possible during pregnancy

A pregnant woman diagnosed with cancer will receive medical care from a multidisciplinary team that consists of an oncologist, a hematologist if she has a blood disorder, a maternal-fetal specialist, a counselor and a social worker.

Treatment decisions depend on the type and stage of cancer, how quickly it is progressing, how far along the pregnancy is and the mother’s personal choices.

No matter the gestational age or type and stage of cancer, we try to avoid harm to the fetus and look out for the mother’s well-being,” Gayle said.

Chemotherapy often can be given safely in the second and early third trimesters. Surgery to remove cancer is generally safe during pregnancy. Radiation can harm the fetus in all trimesters and isn’t given during pregnancy.

Pregnancy may change the course of treatment

Pregnancy can modify investigation and treatment of cancer.

Certain procedures are performed differently for pregnant women, or aren’t performed during pregnancy unless absolutely necessary. A cone biopsy of the cervix usually is postponed until after delivery unless invasive cervical cancer is suspected. In breast cancer, lymph nodes are removed to check for spread of cancer. This procedure is performed on pregnant women without radioactive tracers.

Chemotherapy isn’t given during the first trimester while the baby’s organs are forming or near the end of pregnancy because the patient may end up with low blood counts that can result in excessive bleeding and infection.

Treatment may be delayed until full-term delivery if the cancer is diagnosed later in pregnancy, is early stage and is not progressing. Acute leukemia, metastatic cancer and fast-growing tumors need to be treated right away.

“If the mother’s well-being is at risk, she and her health care team need to discuss whether an early delivery can be done safely or she should terminate the pregnancy,” Gayle said.

Cancer is monitored continually during pregnancy so the treatment plan can be adjusted if the disease progresses.